Actuation lockout for a surgical instrument

ABSTRACT

Surgical instruments and their methods of use are described. In one embodiment, a surgical instrument includes a power transmission including a trigger and a fastener driver operatively coupled to the trigger. Actuation of the trigger from a first configuration to a second configuration moves the fastener driver between at least a first position and a second position. Additionally, an actuation lockout system operatively associated with the power transmission is moveable between a locked configuration and an unlocked configuration. The actuation lockout system prevents movement of the fastener driver from the first position to the second position when the actuation lockout system is in the locked configuration. Actuation of the trigger from the first configuration towards the second configuration moves the actuation lockout system from the locked configuration to the unlocked configuration.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.17/502,850, filed Oct. 15, 2021, which is a continuation of U.S. patentapplication Ser. No. 16/519,540, filed Jul. 23, 2019, which is adivisional application of U.S. patent application Ser. No. 14/755,347,filed on Jun. 30, 2015, each of which is incorporated herein byreference in its entirety.

FIELD

Disclosed embodiments are related to actuation lockouts for surgicalinstruments.

BACKGROUND

Oftentimes a surgical mesh fabric or other prosthetic repair fabric isused during a surgical repair of a hernia or other tissue defect. Theprosthetic repair fabric may be placed in an open procedure orlaparoscopically. To secure the repair fabric in place, one or morefasteners may be deployed through the prosthetic repair fabric and intothe underlying tissue.

SUMMARY

In one embodiment, a surgical instrument includes a power transmissionincluding a trigger and a fastener driver operatively coupled to thetrigger. Actuation of the trigger from a first configuration to a secondconfiguration moves the fastener driver between at least a firstposition and a second position. The surgical instrument further includesan actuation lockout system operatively associated with the powertransmission. The actuation lockout system is moveable between a lockedconfiguration and an unlocked configuration. The actuation lockoutsystem prevents movement of the fastener driver from the first positionto the second position when the actuation lockout system is in thelocked configuration. Actuation of the trigger from the firstconfiguration towards the second configuration moves the actuationlockout system from the locked configuration to the unlockedconfiguration.

In another embodiment, a surgical instrument includes a powertransmission including a trigger and a fastener driver operativelycoupled to the trigger. Actuation of the trigger from a firstconfiguration to a second configuration moves the fastener driverbetween at least a first position and a second position. The surgicalinstrument further includes one or more locking surfaces associated withthe fastener driver and a control surface moveable between a lockedconfiguration and an unlocked configuration when the trigger is actuatedfrom the first configuration towards the second configuration. Thecontrol surface obstructs motion of at least one of the one or morelocking surfaces to prevent motion of the fastener driver between thefirst position and the second position when the control surface is inthe locked configuration.

In a further embodiment, a method of operating a surgical instrumentincludes: initially restraining movement of a fastener driveroperatively associated with a trigger using an actuation lockout system;actuating the trigger from a first configuration towards a secondconfiguration; moving the actuation lockout system from a lockedconfiguration to an unlocked configuration in response to said actuatingof the trigger; and moving the fastener driver from a first position toa second position when the actuation lockout system is in the unlockedconfiguration.

It should be appreciated that the foregoing concepts, and additionalconcepts discussed below, may be arranged in any suitable combination,as the present disclosure is not limited in this respect. Further, otheradvantages and novel features of the present disclosure will becomeapparent from the following detailed description of various non-limitingembodiments when considered in conjunction with the accompanyingfigures.

BRIEF DESCRIPTION OF DRAWINGS

The accompanying drawings are not intended to be drawn to scale. In thedrawings, each identical or nearly identical component that isillustrated in various figures may be represented by a like numeral. Forpurposes of clarity, not every component may be labeled in everydrawing. In the drawings:

FIG. 1 is a schematic representation of a surgical instrument;

FIG. 2 is an exploded view of the distal end of the surgical instrumentof FIG. 1 ;

FIG. 3 is a cross-sectional view of the a surgical instrument handleincluding an actuation lockout system;

FIG. 4 is an exploded view of an actuation lockout system;

FIG. 5 is a perspective view of the actuation lockout system of FIG. 4in a locked configuration;

FIG. 6 is a top view of the actuation lockout system of FIG. 4 in alocked configuration;

FIG. 7 is a perspective view of the actuation lockout system of FIG. 4in an unlocked configuration;

FIG. 8 is a top view of the actuation lockout system of FIG. 4 in anunlocked configuration;

FIG. 9 is a perspective view of a rotation coupling in a coupledconfiguration; and

FIG. 10 is a perspective view of the rotation coupling of FIG. 9 in adecoupled configuration.

DETAILED DESCRIPTION

The inventors have realized the benefits associated with providing asurgical instrument that includes an actuation lockout system thatrestrains and/or prevents movement of a fastener driver until fastenerdeployment is desired. The inventors have recognized that typicalactuation lockout systems require an active step from a user to unlockthe system, such as flipping a separate safety switch, before a surgicaldevice can be actuated. Such active steps can be cumbersome, confusing,and/or inconvenient. Therefore, in some instances, it may be desirableto unlock an actuation lockout system without requiring a separate stepfrom the user. Therefore, the inventors have recognized advantagesassociated with an actuation lockout system that moves from a lockedconfiguration to an unlocked configuration as a trigger is actuated.Such a system eliminates the need for any additional actions by the userto unlock the device, thereby providing a surgical instrument that iseasier and/or more intuitive to operate, and that provides functionalityregardless of whether or not a user remembers to engage/disengage theactuation lockout system.

In some embodiments, a surgical instrument includes a power transmissionwith a trigger operatively coupled to a fastener driver. The powertransmission transfers force applied to the trigger by a user to thefastener driver, which deploys a fastener from a distal end of thesurgical instrument. The power transmission may include any number ofcomponents between the trigger and the fastener driver arranged in anysuitable manner. For example, components that may be included in a powertransmission between the trigger and fastener driver include spur gears,helical gears, crown gears, worm gears, planetary gear systems, belts,clutch interfaces, linkages, or any other appropriate components capableof transmitting power from one component to another. Further,embodiments in which the trigger is directly coupled to the fastenerdriver, as well as embodiments in which the trigger is not coupled tothe fastener driver (e.g., motor driven surgical instruments) are alsocontemplated as the disclosure is not so limited.

Further, it should be understood that the current disclosure is notlimited to any particular type of fastener driver. For example, thefastener driver may be rotationally and/or linearly displaceable forimparting a deployment force to a surgical fastener. In someembodiments, the fastener driver is a rotator formed as a hollow tubeand includes fasteners disposed inside the distal end of the fastenerdriver. Alternatively, the fastener driver may be a solid rod or shaftand may include fasteners disposed on an outer surface of the fastenerdriver such that rotation and/or linear movement of the fastener driverdisplaces the fasteners. In yet other embodiments, the fasteners may belocated distally relative to a distal end of the fastener driver suchthat the distal end of the fastener driver engages with and deploys thefasteners when the fastener driver moves rotationally and/or linearly.Accordingly, it should be understood that a fastener driver may includeany structure capable of transferring a deployment force to a fasteneras the disclosure is not limited to any particular arrangement.

Depending on the particular embodiment, the fastener driver may bearranged to deploy fasteners rotationally and/or linearly; therefore thepower transmission and fastener driver may be configured to provide acorresponding rotational and/or linear force to the fasteners. In onesuch embodiment, actuating a trigger from a first configuration to asecond configuration moves the fastener driver from a first position toa second position. For example, in the case of a rotationally deployedfastener, the fastener driver moves between a first and secondrotational position such that rotation of the fastener driver imparts arotational force to the fastener. Alternatively, in the case of alinearly deployed fastener, the fastener driver moves distally from afirst proximal position to a second distal position such that thefastener driver applies a distally directed force to the fastener. Infurther embodiments, the fastener driver may move both rotationally andlinearly to deploy a fastener. Consequently, it should be understoodthat the current disclosure is not limited to any particulardisplacement direction of the fastener driver such that the fastenerdriver may be displaced axially, rotationally, a combination of the two,or in any other appropriate fashion.

As noted above, a surgical instrument may include an actuation lockoutsystem to prevent actuation of the surgical instrument until the triggeris actuated. The actuation lockout system may be associated with anyportion of the power transmission, including the trigger, fastenerdriver, and/or any intermediate component located between the two.Additionally, the actuation lockout system may selectively preventmovement of the fastener driver that may result, for example, fromvibrations, handling, transport of the surgical instrument, or othersources. By preventing unwanted movements of the fastener driver, theactuation lockout system also prevents associated movement of thesurgical fasteners.

In some embodiments, an actuation lockout system is moveable between alocked configuration, in which movement of the fastener driver isrestrained, and an unlocked configuration in which the fastener driveris free to move to deploy a surgical fastener. In one such embodiment,the actuation lockout system is associated with an appropriate portionof the power transmission such that actuation of the trigger moves theactuation lockout system from the locked to the unlocked configuration.For example, the trigger may be movable between a first initial orunactuated configuration and a second actuated configurationcorresponding to a surgical fastener being deployed from the surgicalinstrument. In the above described system, the actuation lockout systemis configured to be in the locked configuration when the trigger is inthe first configuration. Moving the trigger from the first configurationtowards the second configuration moves the actuation lockout system fromthe locked configuration to the unlocked configuration such that thefastener driver may be displaced (e.g., rotationally and/or linearly) todeploy a fastener.

In some embodiments, the actuation lockout system includes a controlsurface associated with the trigger and one or more locking surfacesassociated with the fastener driver. The one or more locking surfacesare operatively coupled with the fastener driver such that blockingmovement of the one or more locking surfaces prevents movement of thefastener driver. The locking surfaces may either be directly coupledwith the fastener driver, or they may be coupled with another part ofthe power transmission, as the disclosure is not limited to whichspecific part the locking surfaces are positioned on. Regardless oftheir specific location, when the actuation lockout system is in thelocked configuration, the control surface is aligned with a path oftravel of at least one of the locking surfaces. In this manner, thecontrol surface obstructs and/or interferes with movement of the lockingsurface to prevent associated movement of the fastener driver. Asdescribed above, actuation of the trigger moves the actuation lockoutsystem from the locked configuration to the unlocked configuration. Inone embodiment, moving the actuation lockout system to the unlockedconfiguration includes moving the control surface out of alignment withthe path of travel of the locking surfaces such that the control surfaceno longer interferes with and/or obstructs motion of the lockingsurfaces. In other embodiments, moving the actuation lockout system tothe unlocked configuration includes moving the locking surfaces relativeto the control surface, or alternatively moving both the control surfaceand the locking surfaces, to a configuration in which the controlsurface does not obstruct motion of the one or more locking surfaces.Once the one or more locking surfaces are free to move, the fastenerdriver is able to be displaced to deploy a fastener.

It should be understood that the control and/or locking surfaces in anactuation lockout system may include any suitable combination ofcorresponding surfaces that interact with one another to selectivelyblock movement of the locking surfaces when they are aligned with oneanother. For example, the control and/or locking surfaces may includeany appropriate combination of tabs, shoulders, cut outs, pins, grooves,slots, lips, protrusions, or any other suitable structure. In one suchembodiment, the control and locking surfaces include two correspondingtabs that are brought into and out of alignment to move the system intoand out of a locked configuration. In another embodiment, the controland locking surfaces include a pin or similar projecting structure thatis positioned in a corresponding structure capable of capturing the pinsuch as a groove, slot, or hole that is sized, shaped, and oriented, toprevent movement of the pin in a particular direction. Moving the pininto and out of engagement with the corresponding structure selectivelypermits motion of the associated fastener driver. In yet anotherembodiment, the locking surface is a shoulder on the fastener driver, orother suitable portion of the power transmission. The control surfaceincludes a corresponding pin, shoulder, block, or any other structurethat is capable of selectively interfering with movement of the shoulderto move the actuation lockout system between the locked and unlockedconfigurations.

In view of the above, it should be understood that the currentdisclosure is not limited to any particular type or combination ofcontrol and locking surfaces. Therefore, the control and lockingsurfaces may include any suitable combination of structures that may beselectively aligned and/or engaged with one another to selectively blockand/or restrict motion of a fastener driver.

Depending on the particular embodiment, the control surface and the oneor more locking surfaces may move into and out of alignment in anysuitable fashion when the actuation lockout system moves between thelocked and unlocked configurations. Therefore, the actuation lockoutsystem may include any suitable mechanism capable of moving the controlsurface into and out of alignment with the one or more locking surfaceswhen the trigger is actuated. For example, in one embodiment, thecontrol surface is directly coupled to the trigger such that movement ofthe trigger moves the control surface into and out of alignment with thelocking surfaces. Alternatively, the control surface may be indirectlycoupled to the trigger. For example, the control surface may be coupledto the trigger via one or more gears, one or more links, a rack andpinion configuration, complementary camming surfaces, or any otherstructure capable of transferring motion of the trigger to motion of thecontrol surface. In one such embodiment, the control surface is disposedon the face of a gear that is coupled to the trigger either directly, orthrough one or more intermediate gears. Actuation of the trigger fromthe first configuration towards the second configuration drives rotationof the gear to rotate the control surface out of alignment with the pathof travel of the one more locking surfaces. In another embodiment, andas described further below in the figures, the control surface isdisposed on a first link operatively coupled to the trigger. Actuationof the trigger moves the first link linearly and/or rotationallyrelative to the associated locking surfaces.

While several possible configurations have been described related todifferent embodiments for controlling the relative positioning of thelocking and control surfaces of an actuation lockout system, it shouldbe understood that the actuation lockout systems described herein arenot limited to any particular arrangement for controlling the relativemovement of a locking and control surface. For example, although acontrol surface has been described as moving out of alignment with thelocking surfaces, in other embodiments, the locking surfaces may moverelative to a stationary control surface, or alternatively both thecontrol surface and locking surfaces may move relative to each otherwhen the actuation lockout system moves between the locked and unlockedconfigurations. Further, the locking and/or control surfaces may moverelative to each other in any desired manner including, but not limitedto, linearly, rotationally, a combination of linearly and rotationally,as well as along a non-linear path such as a curve to name a few.

It is also noted that the various embodiments of an actuation lockoutsystem disclosed herein are not limited to use with any particular typeof fastener or surgical instrument. For example, an actuation lockoutsystem could be used with a tack, clip, staple, pin, tissue anchor, boneanchor, coil fasteners, screw fasteners, and any other type of fastenerthat could benefit from the use of an actuation lockout system to avoidincomplete and/or unintentional deployment of a fastener. Similarly, theactuation lockout system may be used in any number of medical proceduresincluding, but not limited to, attaching a repair fabric or mesh tounderlying tissue, attaching adjacent layers of tissue, attachingidentification devices and/or tags to livestock, and other appropriateapplications involving the deployment of a fastener.

For the sake of clarity, the embodiments described in relation to thefigures are directed to a laparoscopic fastening instrument. However,the current disclosure is not so limited. Instead, the actuation lockoutsystem could be incorporated in any actuated surgical instrument. Forexample, an actuation lockout system could be employed in an endoscopicdevice, a borescopic device, a catheter, a surgical instrument for usein “open” procedures, surgical instruments including actuated workingtools, or any other appropriate surgical instrument. In embodiments inwhich the surgical instrument deploys fasteners, the surgical instrumentmay be constructed to allow the user to load the instrument with one ormore fasteners, be preloaded with one or more fasteners, be selectivelyconnected with a disposable loading unit including one or more preloadedfasteners, or be constructed in any other appropriate manner.

Turning now to the figures, specific non-limiting embodiments ofactuation lockout systems and surgical instruments are described infurther detail.

FIG. 1 depicts a surgical instrument 10 for deploying one or moresurgical fasteners. The surgical instrument 10 includes a handle 12 at aproximal end of the device and a trigger 14. The surgical instrumentalso includes an outer elongated shaft 16 extending in a distaldirection from the handle. When the trigger is actuated, a surgicalfastener is deployed from a distal tip of the elongated shaft. It shouldbe understood that the deployed surgical fastener may be deployed intoany appropriate prosthetic, bone, and/or tissue. For example, in oneembodiment, a surgical fastener can be deployed into a soft tissuerepair fabric, such as a surgical mesh, as well as into underlyingtissue for repairing a hernia.

FIG. 2 depicts an exploded view of the distal end of the surgicalinstrument 10 of FIG. 1 . As depicted in the figure, the surgicalinstrument includes an outer elongated shaft 16, a rotator 18, and amandrel 20. When assembled, the mandrel is disposed within the rotator,which is disposed within the outer elongated shaft. In the depictedembodiment, the rotator is a rotatable drive tube and the mandrelincludes a threaded portion 22 for supporting one or more surgicalfasteners 100. As shown in the figures, the surgical fasteners may becoil fasteners with a head 102 including a through hole to receive thethreaded mandrel and a coil body 104. As described in more detail below,the trigger is coupled to the rotator via a power transmission, notdepicted, such that actuation of the trigger rotates the rotatorrelative to the mandrel. Rotation of the rotator rotates the surgicalfasteners disposed on the threaded portion of the mandrel, whichdisplaces the fasteners in a distal direction and deploys the distalmost fastener into a prosthetic and/or tissue. A more detaileddescription of this type of fastener deployment system is provided inU.S. application Ser. No. 14/075,398 filed Nov. 8, 2013, published asUS2015/0133964, which is incorporated herein for all purposes.

Referring now to FIG. 3 , the components within an interior of oneembodiment of a surgical instrument 10 are described in more detail. Asillustrated in the figure, the surgical instrument includes a trigger 14and a return spring 24 attached to both the trigger and the handle 12.The return spring provides a restoring force to assist in returning thetrigger to an initial, unactuated configuration when the trigger is inan actuated configuration. The trigger includes teeth 26 configured toengage a corresponding gear of a power transmission 28. In the depictedembodiment, the power transmission includes a gear train arranged toconvert movement of the trigger into rotational motion of the rotator 18to deploy a fastener, as well as a unidirectional gear clutch 30arranged to limit the rotator to rotate in a single direction duringboth the actuation and subsequent release of the trigger. As describedin more detail below, the surgical instrument further includes arotation coupling 32 to allow an operator to selectively rotate therotator and adjust the position of a fastener. The surgical instrumentalso includes an actuation lockout system 40 to restrict movement of therotator 18 until the trigger is actuated; additional details of theactuation lockout system are described below with reference to FIGS. 4-9.

Although a power transmission including a plurality of gears is depictedand described above, it should be understood that other mechanisms orconfigurations also may be used to transfer a force applied to thetrigger to the rotator or other fastener driver. For example, linkagesmay be used to transfer a displacement of the trigger to an associateddisplacement of the fastener driver. Such a configuration may bebeneficial for embodiments employing a linearly displaced fastenerdriver. Alternatively, the trigger may be directly coupled to thefastener driver via a pin joint, rack and pinion configuration, or anyother suitable structure.

In some embodiments, it may be advantageous to limit the movement of arotatable fastener driver to a single rotational direction to helpensure complete deployment of a fastener and to avoid back out of thefastener after it is deployed. Therefore the power transmission mayinclude a one way gear clutch mechanism that only provides a rotationalforce in a single direction. In the depicted embodiment, the gear clutchmechanism 30 includes shoulders that engage with a moveable arm when thegear clutch is rotated in a direction corresponding to deployment of afastener. A biasing element is associated with the arm to help the armengage with the shoulders. When the clutch gear is rotated backwards,for example when the trigger moves from the second (actuated)configuration back to the first (unactuated) configuration, cammingsurfaces on the clutch deflect the arm over the shoulders such that thearm does not engage with the shoulders to drive rotation of the fastenerdriver. In some embodiments, the power transmission further includes aratchet that is configured to only allow the gear train to rotate in asingle direction to further aid in avoiding undesirable back out of afastener.

FIG. 4 is an exploded view of the actuation lockout system 40 of FIG. 3. For the purpose of clarity, many components of the surgicalinstrument, including the handle and power transmission, are notdepicted. The actuation lockout system includes a control tab 70 and aplurality of locking tabs 42. In this embodiment, the control tab isintegrally formed in a movable link as described below. Further, thelocking tabs are disposed on, extend outwardly from, and are distributedcircumferentially around the outer surface of a first half 34 of arotation coupling 32. As described below, the rotation coupling couplesthe trigger to the rotator 18. While corresponding locking and controltabs are depicted in the figures and described above, it should beunderstood that any suitable combination of control and locking surfacesmay be used instead as the disclosure is not so limited.

As illustrated in the depicted embodiment, the position of the controltab 70 is controlled by a linkage coupled to the trigger 14. The linkageincludes a first link 44, on which the control tab is disposed. Thefirst link includes a first channel 56 and a second channel 60 in whicha first pin 54 and an axle 58 are received, respectively. The first pinis attached to a housing 38 of the rotation coupling, and the axle isattached to the handle. In this manner, the channels, first pin, andaxle define a translation path for the first link, which in turn definesa translation path for the control tab 70 disposed on the first link. Inthe depicted embodiment, the first and second channels are arranged suchthat the first link and the control tab reciprocate proximally anddistally along a path that is substantially parallel to an axialdirection of the rotator. However, it should be understood that in otherembodiments, the first link and control tab may be arranged to displacein a direction transverse to the rotator, or in any other suitabledirection, as the present disclosure is not so limited.

The linkage also includes a second link 46 that couples the trigger tothe first link 44. The second link is coupled to the first link via asecond pin 50 connected to the first link. The second pin is received inan elongated slot 52 formed in an end of the second link. Further, anopposing end of the second link is directly coupled to the trigger via abiased pin joint including a third pin 48 and torsion spring 66. Thetorsion spring has a first end 68 a that is coupled to a portion of thetrigger and a second end 68 b that is received by a hook 64 disposed onthe second link. Consequently, the torsion spring provides a rotationalbias to the second link, which facilitates movement of the actuationlockout system from the locked configuration to the unlockedconfiguration, as described in more detail below. Although a torsionspring is depicted, it should be understood that the current disclosureis not limited to a specific type of biasing element. In otherembodiments, other biasing elements, such as compression springs,elastic rods or bands, elastic arms, or any other structure capable ofbiasing the second link in an appropriate direction may be used.

Having described the various components of the actuation lockout system40, its method of use is described in more detail with reference toFIGS. 5-8 . FIGS. 5-6 depict an actuation lockout system 40 in thelocked configuration, i.e., before actuation of the trigger 14. In thelocked configuration, movement of the second link 46 due to the biasingforce from the torsion spring 66 is limited by a control pin 62 toprevent the actuation lockout system from moving to the unlockedconfiguration before actuation of the trigger. As illustrated in FIG. 6, when the actuation lockout system is in the locked configuration, thecontrol tab 70 is aligned with a path of travel of the locking tabs 42to block movement of the locking tabs. Therefore, the rotator, which isassociated with the locking tabs, is also restrained from moving.

FIGS. 7-8 depict an actuation lockout system 40 in the unlockedconfiguration. Actuation of the trigger 14 along direction A from afirst configuration (e.g., an unactuated configuration) towards a secondconfiguration (e.g., an actuated configuration in which a fastener isfully deployed) causes an associated displacement of the second link 46in direction B, and the torsion spring 66 provides a rotational biasingforce about the third pin 48 in direction C to urge the actuationlockout system towards the unlocked configuration. Specifically, therotational force is transferred to the first link 44 via the second pin50 received in slot 52, and therefore provides a linear force to thefirst link, which in turn, causes displacement of the first link indirection D. As illustrated in FIG. 7 , translation of the first linkmoves the control tab 70 out of alignment with a path of travel of thelocking tabs 42 such that the locking tabs are free to move in directionE during subsequent portions of the actuation cycle. As a result, therotator 18 is also free to rotate as shown by arrow F.

Rotation of the locking tabs (disposed on the first half 34 of therotation coupling) and the associated rotator is driven by the powertransmission (not depicted). When the trigger moves from the secondposition back towards the first position, for example due to a biasingforce provided by the return spring 24, the motion of the first andsecond links are reversed to move the actuation lockout system back intothe locked configuration. Therefore, the process of initiallyrestricting and subsequently permitting rotation of the rotator occursduring each actuation of the surgical instrument.

To ensure appropriate positioning of a stack of surgical fastenerspositioned within a surgical instrument during manufacture, it may bedesirable to permit the rotation of a rotatable fastener driver withoutrequiring full disassembly of the instrument. Therefore, and asdescribed above, in some embodiments, a surgical instrument includes arotation coupling that selectively allows rotation of the rotator 18, orother appropriate fastener driver, to adjust the position of thefasteners 100 along a mandrel 20. For example, FIG. 9 depicts oneembodiment of a rotation coupling 32 in a coupled configuration suchthat a rotational force from the power transmission is transferredthrough the rotation coupling to the rotator. In the depictedembodiment, the rotation coupling includes a first half 34 coupled tothe power transmission, and a second half 36 coupled to the rotator. Thefirst half of the coupling is coupled to a shaft gear 28 a of the powertransmission via a key fit (not depicted). The key fit forms a slidableconnection between the first half of the coupling and the shaft gearsuch that the coupling may be slid both proximally and distally on theshaft gear. The first and second halves of the coupling interact withone another at an interface 74. In the depicted embodiment, theinterface includes interlocking features, such as interlockingcrenellated structures. However, it should be understood that theinterface may correspond to any number of interfaces including, but notlimited to, an interference fit, a nut and bolt connection, or any othersuitable structure capable of transferring a rotational force betweenthe first half and the second half of the coupling and that may beselectively engaged and disengaged to couple and decouple a fastenerdriver from an associated trigger. In the depicted embodiment, apre-compressed spring 74 is positioned between opposing surfaces of aroller bearing 76 and the first half of the coupling 34. Thus, the firsthalf of the coupling is biased in a distal direction towards the secondhalf of the coupling which corresponds to an engaged configuration. Asillustrated in FIG. 10 , when it is desired to decouple the rotator fromthe trigger for rotating the rotator, a user displaces the first half ofthe coupling in a proximally oriented direction G to move the interface72 out of engagement. The rotator is then decoupled from the trigger andmay be freely rotated in direction H to adjust the position of a stackof fasteners as required. Once appropriately positioned, the first halfof the coupling is released. After being released, the first half of thecoupling is then displaced distally by the biasing spring to reengagethe interface between the coupling halves and recouple the rotator withthe trigger.

While the present teachings have been described in conjunction withvarious embodiments and examples, it is not intended that the presentteachings be limited to such embodiments or examples. On the contrary,the present teachings encompass various alternatives, modifications, andequivalents, as will be appreciated by those of skill in the art.Accordingly, the foregoing description and drawings are by way ofexample only.

1. A method of operating a surgical instrument, the method comprising:initially blocking movement of one or more tabs associated with andextending outward relative to an axial direction of a rotational driverwith a first link, wherein the first link obstructs motion of the one ormore tabs associated with the rotational driver; actuating a triggeroperatively coupled with the first link from a first configuration to asecond configuration; moving the first link out of a path of travel ofthe one or more tabs; and rotating the rotational driver when the firstlink is in out of the path of travel of the one or more tabs.
 2. Themethod of claim 1, wherein moving the first link from a lockedconfiguration to an unlocked configuration includes moving a control tabassociated with the first link out of alignment with the path of travelof the one or more tabs.
 3. The method of claim 2, wherein the controltab is aligned with the path of travel of the one or more tabs when thefirst link is in the locked configuration.
 4. The method of claim 2,further comprising moving the first link to move the control tab out ofalignment with the path of travel of the one or more tabs as the triggeris actuated from the first configuration towards the secondconfiguration.
 5. The method of claim 2, wherein the control tab isdisposed on the first link.
 6. The method of claim 2, wherein actuatingthe trigger from the first configuration towards the secondconfiguration includes moving the first link to move the control tabfrom the locked configuration to the unlocked configuration.
 7. Themethod of claim 1, further comprising transferring rotational motionfrom the trigger to the first link via a second link directly coupled tothe trigger and the first link.
 8. The method of claim 1, wherein thefirst configuration of the trigger is an unactuated configuration andthe second configuration of the trigger is a fully actuatedconfiguration.
 9. The method of claim 1, further comprising positioningthe first link in the path of travel of the one or more tabs to preventactuation of the rotational driver.
 10. The method of claim 1, furthercomprising moving a first coupling and a second coupling of a rotationcoupling relative to one another between an engaged configuration inwhich the rotational driver is coupled to the trigger and a disengagedconfiguration in which the rotational driver is decoupled from thetrigger, wherein the first coupling is operatively coupled to thetrigger, wherein the second coupling is operatively coupled to therotational driver.
 11. The method of claim 10, further comprisingadjusting a position of a stack of fasteners in the rotational driverwhen the first and second couplings are in the disengaged configuration.12. The method of claim 10, further comprising biasing the first andsecond couplings towards the engaged configuration with a spring of therotation coupling.
 13. The method of claim 10, further comprising movingan actuation lockout system operatively associated with the rotationaldriver and the trigger between a locked configuration and an unlockedconfiguration, wherein the actuation lockout system comprises the one ormore tabs and a control tab.
 14. The method of claim 13, furthercomprising preventing rotation of the rotational driver when theactuation lockout system is in the locked configuration with theactuation lockout system.
 15. The method of claim 13, wherein the one ormore tabs extend outward relative to an axial direction of therotational driver, wherein the one or more tabs are distributedcircumferentially around the first coupling.
 16. The method of claim 13,further comprising moving the control tab in a direction parallel to anaxial direction of the rotational driver.